Method for crimping a prosthetic valve

ABSTRACT

A method of crimping a prosthetic valve on a delivery catheter having an inflatable balloon includes releasably attaching a holding mechanism to a shaft of the delivery catheter, wherein the holding mechanism is connected to a crimping device, positioning the prosthetic valve in the crimping device, actuating the crimping device to radially crimp the prosthetic valve onto the balloon or onto the shaft of the delivery catheter at a location adjacent the balloon, and removing the holding mechanism from the delivery catheter after crimping the prosthetic valve.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.18/306,842, filed Apr. 25, 2023, which is a divisional of U.S. patentapplication Ser. No. 16/415,590, filed on May 17, 2019, now U.S. Pat.No. 11,666,436, which is a continuation of U.S. patent application Ser.No. 15/063,319, filed Mar. 7, 2016, now U.S. Pat. No. 10,307,250, whichis a continuation of U.S. patent application Ser. No. 14/665,677, filedMar. 23, 2015, now U.S. Pat. No. 9,277,992, which is a continuation ofU.S. patent application Ser. No. 14/181,425, filed Feb. 14, 2014, nowU.S. Pat. No. 8,986,320, which is a continuation of U.S. patentapplication Ser. No. 13/715,605, filed Dec. 14, 2012, now U.S. Pat. No.8,652,145, which claims the benefit of U.S. Patent Application No.61/570,517, filed Dec. 14, 2011, the entire disclosures of which areincorporated by reference.

FIELD

This disclosure relates to systems and methods for crimping a prostheticvalve for delivery into a body.

SUMMARY

Disclosed herein are embodiments of systems and devices for crimping aprosthetic valve, and related methods. Some exemplary systems comprise aradially expandable and compressible prosthetic valve, a crimping devicepositioned around the valve and configured to reduce the diameter of thevalve to a delivery configuration, and a sterile package enclosing thevalve and the crimping device. The valve can be pre-assembled in apartially crimped configuration within the crimping device. Afterremoving the sterile packaging, the crimping device can be used to crimpthe valve from the partially crimped configuration to the deliveryconfiguration, such as by twisting a knob on the crimping device. Thesystem can further comprise at least a portion of a delivery catheterwithin the sterile package, wherein the valve is pre-mounted on oradjacent to an inflatable balloon of the delivery catheter, and thevalve is crimped onto the delivery catheter using the crimping device.

The crimping device can comprise a radially compressible colletpositioned around the valve and a rotatable knob coupled to the collet,wherein rotation of the knob causes radial compression of the collet andcrimping of the valve. The crimping device can further comprise areleasable holding mechanism configured to releasably grip a shaft of adelivery catheter to maintain a position of the crimping device relativeto the shaft.

Some embodiments of the system can further comprise a loader coupled toan end of the crimping device within the sterile package. The loader canbe configured to receive the valve, in the delivery configuration, fromthe crimping device. In some embodiments, the loader can be separatelycoupled to the crimping device after the device is removed from thepackage.

Some embodiments of a crimping device comprise a radially compressiblecollet configured to house a prosthetic valve and comprising a firstaxial end portion, an opposing second axial end portion, and anintermediate portion between the first and second axial end portions.The first and second axial end portions are each tapered from a greaterouter diameter adjacent to the intermediate portion to a lesser outerdiameter proximate the respective axial ends of the collet. The devicefurther comprises a mechanism for radially compressing the collet inorder to crimp the valve onto a delivery catheter. The collet can beconfigured to receive a prosthetic valve in a partially crimpedconfiguration, and the mechanism can be configured to crimp the valvefrom the partially crimped configuration to a delivery configuration.The intermediate portion of the collet can have an outer diameter thatis less than the outer diameter of the first and second axial endportions immediately adjacent to the intermediate portion. The colletcan comprise a plurality of elongated members positioned side-by-side ina cylindrical arrangement, with each elongated member being connected toa first neighboring elongated member at a first end and connected to asecond neighboring elongated member at a second, opposite end. Thedevice can further comprise a pusher comprising an internally taperedsurface that is configured to slide over a corresponding externallytapered surface of the first axial end portion of the collet to compressthe collet. The device can further comprise a rotatable knob coupled tothe collet such that rotation of the knob causes compression of thecollet. In some embodiments, further rotation of the knob in the samedirection releases pressure on the collet and allows the collet toexpand.

An exemplary method for crimping a prosthetic valve comprises: receivinga prosthetic valve pre-assembled within a crimping device in a sterilepackage; removing the crimping device and valve from the sterilepackage; and, using the crimping device, crimping the valve to adelivery configuration onto a delivery catheter. The valve can bepre-assembled within the crimping device in a partially crimpedconfiguration. Crimping the valve can comprise radially compressing thevalve from a partially crimped configuration to the deliveryconfiguration with the valve mounted on the delivery catheter, and thenreleasing compression on the valve from the crimping device. Radiallycompressing the valve can comprise rotating a knob of the crimpingdevice from a first position to a second position, and releasingcompression on the valve can comprise further rotating the knob from thesecond position to a third position. The method can further comprisereleasing the crimping device from the delivery catheter by furtherrotating the knob from the third position to a fourth position, therebypermitting axial movement of the delivery catheter relative to thecrimping device. The method can further comprise advancing the valve outof a distal outlet of the crimping device and directly into a loader.Advancing the valve can comprise coupling the distal outlet of thecrimping device to an inlet of the loader that is already coupled to apatient.

The foregoing and other objects, features, and advantages of theinvention will become more apparent from the following detaileddescription, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary valve crimping systemdisclosed herein.

FIG. 2 is a partial cut-away view of the system of FIG. 1 .

FIG. 3 is a perspective view of another exemplary valve crimping systemdisclosed herein.

FIGS. 4 and 5 are exploded views of the system shown in FIG. 1 .

FIGS. 6 and 7 are perspective views of exemplary collets disclosedherein.

FIGS. 8-11 are cross-sectional side views of the exemplary system shownin FIG. 1 .

FIGS. 12 and 13 are partial cut-away side views of the system shown inFIG. 1 , illustrating an exemplary releasable holding mechanism.

FIGS. 14-21C show alternative valve crimping systems disclosed herein.

DETAILED DESCRIPTION

FIGS. 1-3 show exemplary systems for crimping a prosthetic valve andother crimpable, implantable medical devices, such as stents, grafts,etc. The illustrated systems comprise a crimping device 10 and aradially expandable and compressible prosthetic valve 12 positionedwithin the crimping device. The crimping device 10 is configured toreduce the diameter of the valve 12 to a delivery configuration fordelivery into a patient.

The exemplary system shown in FIG. 1 further comprises at least aportion of a delivery catheter 14, such that valve 12 and the crimpingdevice 10 are positioned around and mounted on the delivery catheter 14.The exemplary system shown in FIG. 2 further comprises a sterile package16 enclosing an assembly comprised of the crimping device 10, the valve12, and at least a portion of the delivery catheter 14. In anotherembodiment, the system can comprise the crimping device 10 positionedaround the valve 12 and enclosed within the sterile package 16 withoutany portion of the delivery catheter 14. In some of these embodiments,the delivery catheter 14 can be separately provided within anothersterile package and later combined with the crimping device 10 and valve12 when ready to be used. The exemplary embodiment shown in FIG. 3further comprises an optional loader 18 coupled to a distal end of thecrimping device 10.

These systems can come pre-assembled in a sterile package 16 such thatthe system can be removed from the package just prior to the crimpingdevice 10 being used to crimp the valve 12 to a delivery configurationonto the delivery catheter 14 and then delivering the valve into apatient. The components can be sealed within the sterile package 16 in awet state or a dry state. In a wet state, a sterilization fluid can beincluded within the sterile package 16. In a dry state, the leaflets ofthe valve 12 (typically made from bovine pericardium tissue or othernatural or synthetic tissues) desirably are completely or substantiallydehydrated and the package 16 desirably is free of any liquid.

The prosthetic valve 12 can comprise any radially collapsible andexpandable prosthetic valve, such as a prosthetic heart valve. The valve12 can be radially collapsible and expandable between an expandedconfiguration and a delivery configuration. The valve 12 can beself-expandable or balloon (plastically) expandable. In someembodiments, the valve 12 can be in a partially crimped configurationprior to being assembled within the crimping device 10. For example, thevalve can be pre-crimped to the partially crimped configuration usinganother crimping instrument, prior to being assembled into crimpingdevice 10. In the partially crimped configuration, the valve 12 has anouter diameter that is between that of the expanded configuration andthat of the delivery configuration. In some embodiments, the valve 12can have an outer diameter in the partially crimped configuration thatis closer to the outer diameter in the delivery configuration than tothe outer diameter in the expanded configuration. For example, the valve12 in the partially crimped configuration can be crimped about 75% ofthe way from the expanded configuration to the delivery configuration.The crimping device 10 can also be configured to crimp the valve 12 tothe delivery configuration from the expanded configuration without firstpre-crimping the valve to an intermediate partially crimpedconfiguration.

After the valve 12 is crimped onto the delivery catheter 14 in thedelivery configuration, the valve can be removed from the crimpingdevice 10. In some embodiments, the valve 12 and catheter 14 can beretracted proximally out of and separated from the crimping device 10.In other embodiments, the valve 12 and the delivery catheter 14 can beadvanced distally through a distal outlet 86 of the crimping device 10such that the crimping device remains positioned around a portion of thedelivery catheter that is proximal to the valve 12. In otherembodiments, the crimping device 10 can be configured to separate intopieces or open, such as like a clam shell, such that the crimping device10 can be removed laterally from the catheter 14 and valve 12. After thevalve 12 is removed from the crimping device 10, the valve and catheter14 can be introduced into a patient.

FIGS. 4 and 5 show exploded views of the system shown in FIG. 1 . Asshown in FIG. 6 , the crimping device 10 can comprise a collet 20 thatis configured to house the valve 12 within the collet. The collet 20 isconfigured to be resiliently compressible in a radial direction suchthat radial compression on the collet 20 can cause crimping of the valve12 positioned within the collet. The collet 20 can further besubstantially non-compressible in the axial direction. In the embodimentshown in FIG. 6 , the collet 20 comprises a plurality of elongatedmembers 22 positioned side-by-side in a cylindrical arrangement, witheach elongated member 22 being connected to a first neighboringelongated member at a first axial end 24 and being connected to a secondneighboring elongated member at a second, opposite axial end 26. In anuncompressed state, as shown in FIG. 6 , each elongated member 22 canform a first angle α with each of the two adjacent elongated members,and the collet 20 can have a first inner diameter D_(I). As the collet20 is radially compressed, the elongated members 22 can pivot towardsone another about the axial ends 24, 26, reducing the angle α andreducing the inner diameter D_(I). FIG. 7 shows an alternativeembodiment of the collet 20A that comprises elongated members 28 thatare curved along their axial length. The collets 20 or 20A can compriseflexible material, such as metal or plastic, for example HDPE orsilicone. In some embodiments, a protective sleeve can be positionedalong the internal surface of the collet 20 to protect the valve 12 fromdamage from the collet during crimping.

As shown in FIG. 6 , the collet 20 can comprise a first axial endportion 30, an opposing second axial end portion 32, and an intermediateportion 34 between the first and second axial end portions. The firstand second axial end portions 30, 32 are each tapered from a greaterouter diameter adjacent the intermediate portion 34 to a lesser outerdiameter proximate the respective axial ends of the collet 20. Thecollet 20 further comprises a pair of opposing step-down portions, orsteps, 36, 38 positioned between the intermediate portion 34 and theaxial end portions 30, 32, respectively. The intermediate portion 34 ofthe collet has a reduced outer diameter between the steps 36, 38 that isless than the outer diameter of the first and second axial end portions30, 32 immediately adjacent to the steps.

As shown in FIG. 5 , the crimping device can further comprise a rigidhousing 40 within which the collet 20 is positioned. The housing 40 canbe generally cylindrical with an externally threaded portion 42 at adistal end and a flared portion 44 at a proximal end.

The crimping device 10 can further comprise a stop 60 that is secured tothe flared portion 44 of the housing 40 via a pair of screws 62. Thestop 60 can comprise a tapered wall 66 that is configured to restrictthe axial position of the collet 20 in the proximal direction relativeto the housing 40 and the stop 60. The wall 66 can be configured tomatch the tapered shape of the proximal end portion 30 of the collet 20.

The crimping device 10 can further comprise a pusher 70 that isgenerally cylindrical and fits within the distal end 42 of the housing40. The pusher 70 defines an opening at its proximal end that isconfigured to receive the distal end portion 32 of the collet 20. Asshown in FIG. 8 , the pusher 70 comprises an internal annular ledge 72at its proximal end that is configured to slidably engage the taperedexternal surface of the distal end portion 32 of the collet 20. As thepusher 70 is urged proximally against the collet 20, the annular ledge72 imparts axial force in the proximal direction as well as radiallyinward force against the distal end portion 32 of the collet.

As shown in FIG. 8 , the housing 40 can further comprise an internalannular ledge 48 that is configured to slidably engage the taperedexternal surface of the proximal end portion 30 of the collet. As thepusher 70 moves proximally relative to the housing 40, the internalannular ledges 48 and 72 become closer together and cooperate to pinchthe collet 20 between them. As the collet 20 is pinched, the annularledges 48, 72 slide along the respective axial end portions 30, 32 ofthe collet toward the intermediate portion 34. This causes the collet 20to radially compress.

In the embodiment of the crimping device 10 shown in FIG. 8 , the endportions 30, 32 of the collet 20 and the internal annular ledges 48, 72are tapered. This embodiment is shown in FIG. 21A. FIG. 21B shows analternative embodiment of the crimping device 10 comprising a collet 21that comprises non-tapered end portions 31 and 33. The non-tapered endportions 31, 33 are still greater in diameter than the intermediateportion 34 of the collet. Even though the end portions 31, 33 are nottapered, because the internal annular ledges 48 and 72 are tapered, thecrimping device 10 can still function in the same manner as theembodiment shown in FIG. 21A. FIG. 21C shows yet another alternativeembodiment of the crimping device 10 comprising the same collet 20 as inFIG. 21A, but wherein the internal annular ledges 49 and 73 are nottapered. Like with the embodiment of FIG. 21B, the embodiment of FIG.21C can still function in the same manner as the embodiment of FIG. 21A.

The crimping device 10 can further comprise a rotatable knob 80 that isinternally threaded and positioned around and engaged with theexternally threaded end portion 42 of the housing 40. The knob 80 cansurround the pusher 70 such that axial movement of the knob 80 in theproximal direction causes corresponding axial movement of the pusher 70.The engagement of the inner threads 82 of the knob 80 with the externalthreads 42 of the housing 40 can be such that rotation of the knob 80 inone direction relative to the housing 40 causes the knob to moveproximally relative to the housing. Rotation of the knob 80 in theopposite direction can cause the knob to move distally relative to thehousing 40. Thus, rotation of the knob 80 relative to the housing 40 canurge the pusher 70 against the collet 20 thereby pinching the colletbetween the internal annular ledges 48, 72 and causing the collet toradially compress.

The crimping device 10 can further comprise an external casing 90 thatis secured around the proximal flared end 44 of the housing 40. Thecasing 90 can be fixed relative to the housing 40 and serve as hand gripfor a user. The casing 90 can be generally cylindrical and can besecured to the housing 40 and the stop 60 via the screws 62.

The crimping device 10 can further comprise a releasable holdingmechanism configured to releasably grip a shaft of a delivery catheter14 to maintain a position of the crimping device relative to the shaft.An exemplary holding mechanism comprises a pair of clamping jaws 100that are pivotable about the flared end 44 of the housing 40, as shownin FIGS. 8-13 . As shown in FIG. 5 , each jaw 100 can comprise a hinge102 that is pivotally coupled to a tang 104 protruding from the flaredend 44 of the housing 40. The jaws 100 further comprise a clampingportion 106 configured to grip onto the delivery catheter 14. A pair ofsprings, or other similar mechanism, can couple the two jaws 100together such that they are biased toward each other and a separationforce is needed to separate the clamping portions 106 from the deliverycatheter 14. For example, FIGS. 12 and 13 show a spring 108 coupled ateach end to a spring seat 110 of each jaw 100. The spring 108 isconfigured to resiliently extend under a separation force to allow thejaws 100 to open, and resiliently contract to reclose the jaws when theseparation force is removed.

The crimping device 10 can further comprise a set of pushrods 50positioned between the knob 80 and the jaws 100 that can provide theseparation force needed to open the jaws 100, as shown in FIGS. 12 and13 . The pushrods 50 can be coupled in pairs by arched portions 52, asshown in FIG. 5 , such that the pushrods can slide axially along theouter surface of the housing 40. The pushrods 50 can extend axiallythrough apertures 46 in the flared end 44 of the housing and throughapertures 64 in the stop 60, and can contact a distal surface of thejaws 100, as shown in FIG. 12 . As the knob 80 rotates to compress thecollet 20 and the valve 12, a proximal surface 84 of the knob movesdistally toward the arched portions 52, as shown in FIGS. 8-10 . Whenthe proximal surface 84 of the knob contacts the arched portions 52, thepushrods 50 are urged proximally against the jaws 100, causing the jawsto pivot about the hinges 102 against the force of the spring 108 andreleasing the jaws 100 from the delivery catheter 14, as shown in FIGS.11 and 13 .

FIG. 8 shows an initial configuration of the crimping device 10 with avalve 12 positioned within the collet 20 and a delivery catheter 14extending axially through the device 10 and the valve 12. For example,this is the configuration the system can be in when the sterile package16 is opened in the operating room when a physician is ready to deliverthe valve into a patient. In this configuration, the valve 12 ispremounted, but not fully crimped, at the desired location on thedelivery catheter (a balloon catheter in the illustrated example) fordelivery of the valve with final crimping to be performed by thephysician just prior to implantation. In this manner, the physician neednot perform the additional step of locating the valve at the desiredlocation on the delivery catheter. In addition, because the valve can bepackaged and sold in a precrimped configuration, the crimping device 10is much smaller, lighter, and easier to use than conventional crimpingdevices that are designed to crimp a fully expanded valve.

In the initial configuration of FIG. 8 , the collet 20 and the valve 12are not under compression, or are under minimal compression, from therest of the crimping device 10. As the knob 80 is rotated relative tothe housing 40 (e.g., the doctor can grip the knob with one hand and thecasing 90 with the other hand and twist them relative to each other),the knob 80 moves proximally relative to the housing 40 and urges thepusher 70 against the collet 20, pinching the collet between theinternal annular ledges 48 and 72. As the knob 80 rotates and thedistance between the ledges 48, 72 decreases, the ledges slide “up” thetapered surfaces of the end portions 30, 32, respectively, of the collet20, causing the collet to compress radially.

FIG. 9 shows the crimping device at a fully crimped configurationwherein the ledges 48, 72 have slid all the way up the tapered endportions 30, 32 of the collet. In this configuration, the collet 20 isradially compressed to a furthest extent, compressing the valve 12 to adelivery configuration onto the catheter 14. The valve 12 can be crimpedonto an inflatable balloon 15 of the delivery catheter, or crimped ontoanother portion of the delivery catheter that is just proximal to aninflatable balloon 15, as shown in FIG. 9 , or distal to the balloon. Incases where the valve is mounted proximal or distal to the balloon, thevalve can be repositioned onto the balloon for deployment after thevalve and delivery catheter are inserted into the body. Examples ofdelivery catheters that can be used to introduce a valve into thevasculature of a patient in a position proximal or distal to a balloonare described in U.S. Patent Publication 2009/0281619, filed Oct. 8,2008, which is incorporated herein by reference.

As shown in FIG. 10 , additional rotation of the knob 80 in the samedirection causes the ledges 48, 72 to slide over steps 36, 38,respectively, between the end portions 30, 32 and the intermediateportion 34 of the collet. As the ledges slide over the steps and intothe intermediate portion 34, the collet 20 is allowed to radially expanda small amount, releasing compression on the valve 12. In addition, aclicking noise can be made as the ledges 48, 72 slide over the steps 36,38, providing an audible indication for the doctor. In the case of aballoon expandable valve 12, the valve can remain in the deliveryconfiguration while the collet 20 expands radially apart from the valve,releasing the valve enough to be slid axially out of the collet.

As shown in FIG. 10 , the proximal end 84 of the knob 80 can contact thearched portions 52 of the pushrods 50 at the same time as, or justafter, the ledges 48, 72 slide over the steps 36, 38 and the collet 20is released. Further rotation of the knob 80 causes the knob 80 to pushthe pushrods 50 into the jaws 100, causing the jaws to pivot about thehinges 102 (as shown in FIGS. 11 and 13 ) and separate from the deliverycatheter 14. At this point, the valve 12 is released from the collet 20and the jaws 100 are released from the catheter 14, allowing thecatheter with the valve mounted on it to be pulled proximally out of thecrimping device 10, advanced distally through the device, or otherwiseremoved from the device.

In the embodiment shown in FIG. 3 , for example, the valve 12 can beadvanced through a distal outlet 86 of the crimping device 10 and into aloader 18 coupled to the distal end of the crimping device. The loader18 can be a tubular structure configured to contain the valve 12 in thedelivery configuration. The distal end of the loader 18 can be insertedinto another device, such as an introducer sheath, which is alreadyinserted into a patient, for percutaneous delivery of the valve 12 outof the loader 18 and into the patient.

FIGS. 14-17 show an alternative embodiment of a crimping device 200,which comprises a housing 202, a proximal end cap 204, and a distalloader 206. The housing 202 can contain a screw-actuated crimper 208that comprises a coiled wire frame 210, a first end 211 of which iscoupled to a first member 212 of the crimper and a second end 213 ofwhich is coupled to a second member 214 of the crimper. Rotation of ascrew knob 215 can move the second member 214 relative to the firstmember 212, thereby increasing or decreasing the diameter of the coiledwire frame 210, and thereby crimping or releasing a prosthetic valve 216positioned within the coiled wire frame 210. A delivery catheter (notshown) can extend through the end cap 204 and through the valve 216 suchthat the valve can be crimped onto the delivery catheter. The deliverycatheter with the valve 216 mounted thereon can then be retractedproximally out of the crimping device 200 or advanced through thecrimping device, through the loader 206 and an introducer sheath, andinto a patient.

FIGS. 18 and 19 show another alternative embodiment of a crimping device300, which comprises a coiled wire frame 302 coupled at a first end 303to a first member 304 and coupled at a second end 305 to a second member306. A valve 307 positioned within the wire frame 302 can be crimped bytwisting a screw knob 308, which changes the diameter of the wire frame302 by moving the first member 304 relative to the second member 306.The crimping device 300 can be used to crimp the valve 307 onto adelivery catheter (not shown) prior to insertion into a patient.

FIG. 20 shows another alternative embodiment of a crimping device 400,which comprises a coiled wire frame 402 coupled at a first end 403 to afirst member 404 and coupled at a second end 405 to a second member 406.A valve (not shown) positioned within the wire frame 402 can be crimpedby twisting a screw knob 407, which changes the diameter of the wireframe 402 by moving the first member 404 relative to the second member406. The crimping device 400 can be used to crimp a valve onto adelivery catheter prior to insertion into a patient.

Each of the crimping devices 200, 300 and 400 can be pre-assembled in asterile package with a valve positioned within the device. At least partof a delivery catheter can also be pre-assembled with the crimpingdevices 200, 300, 400 within a sterile package.

In view of the many possible embodiments to which the principles of thedisclosed invention may be applied, it should be recognized that theillustrated embodiments are only preferred examples of the invention andshould not be taken as limiting the scope of the invention. Rather, thescope of the invention is defined by the following claims. We thereforeclaim as our invention all that comes within the scope and spirit ofthese claims.

We claim:
 1. A method of crimping a prosthetic valve on a deliverycatheter having an inflatable balloon, the method comprising: releasablyattaching a holding mechanism to a shaft of the delivery catheter,wherein the holding mechanism is connected to a crimping device;positioning the prosthetic valve in the crimping device; actuating thecrimping device to radially crimp the prosthetic valve onto the balloonor onto the shaft of the delivery catheter at a location adjacent theballoon; and removing the holding mechanism from the delivery catheterafter crimping the prosthetic valve.
 2. The method of claim 1, whereinthe holding mechanism is at a location proximal to the balloon when theholding mechanism is releasably attached to the shaft.
 3. The method ofclaim 1, wherein the holding mechanism is configured to clamp onto anouter surface of the shaft of the delivery catheter.
 4. The method ofclaim 3, wherein the holding mechanism comprises clamping jawsconfigured to clamp onto the outer surface of the shaft of the deliverycatheter.
 5. The method of claim 4, wherein removing the holdingmechanism from the delivery catheter comprises pivoting clamping jawsaway from the outer surface of the shaft.
 6. The method of claim 1,wherein the prosthetic valve is crimped onto the balloon.
 7. The methodof claim 1, wherein the prosthetic valve is crimped onto the shaft ofthe delivery apparatus.
 8. The method of claim 1, wherein the prostheticvalve is plastically expandable.
 9. The method of claim 1, whereinactuating the crimping device comprises rotating a knob of the crimpingdevice while the prosthetic valve is inside of the crimping device. 10.A method of crimping a prosthetic valve on a delivery catheter having aninflatable balloon, the method comprising: releasably attaching aholding mechanism to a shaft of the delivery catheter, wherein theholding mechanism is connected to a crimping device; positioning theprosthetic valve in the crimping device and around the balloon;actuating the crimping device to radially crimp the prosthetic valvefrom a radially expanded state to a radially compressed on the balloon;and removing the holding mechanism from the delivery catheter.
 11. Themethod of claim 10, wherein the holding mechanism is at a locationproximal to the balloon when the holding mechanism is releasablyattached to the shaft.
 12. The method of claim 10, wherein the holdingmechanism is configured to clamp onto an outer surface of the shaft ofthe delivery catheter.
 13. The method of claim 12, wherein the holdingmechanism comprises clamping jaws configured to clamp onto the outersurface of the shaft of the delivery catheter.
 14. The method of claim13, wherein removing the holding mechanism from the delivery cathetercomprises pivoting clamping jaws away from the outer surface of theshaft.
 15. The method of claim 10, wherein the prosthetic valve isplastically expandable.
 16. The method of claim 10, wherein actuatingthe crimping device comprises rotating a knob of a crimping device whilethe prosthetic valve is inside of the crimping device.
 17. A method ofcrimping a prosthetic valve on a delivery catheter having an inflatableballoon, the method comprising: positioning the prosthetic valve withina crimping device and around the balloon of the delivery catheter,wherein the crimping device is connected to a holding mechanism that isclamped onto an outer surface of a shaft of the delivery catheter at alocation proximal to the balloon; actuating the crimping device toradially crimp the prosthetic valve from a radially expanded state to aradially compressed onto the balloon; and removing the holding mechanismfrom the delivery catheter.
 18. The method of claim 17, whereinactuating the crimping device comprises rotating a knob of a crimpingdevice while the prosthetic valve is inside of the crimping device. 19.The method of claim 17, wherein removing the holding mechanism from thedelivery catheter comprises moving clamping members of the holdingmechanism away from the outer surface of the shaft of the deliverycatheter.